STRENUIS AND
LA CEDUNT
15 November 1990
INSTITUTE OF CRYOGENICS
THE UNIVERSITY SOUTHAMPTON SO9 5NH
Telex:
47661
Telephone: Fax:
(0703) 592050 (0703) 593053
The Governor Government House
Hong Kong
Your Excellency
Re: The study by the Hong Kong Prison Service on the relation between heavy metals and violence in prisoners
In The Observer, Sunday 11 November 1990 was an article (copy enclosed) describing a study by the Hong Kong Prison Service which reveals a relationship between the presence of heavy metals in the body and violence in prisoners. We have been studying the decontamination of people from heavy metal poisoning and it is possible that these people can be decontaminated. Further our work suggests that these people can be identified quickly in two ways. First, by the presence of methane on the breath and second, by the absence of black stools when they are fed dietary iron supplements. At present we are working with the Ukrainians on the decontamination of people suffering from the Chernobyl accident. In the following paragraphs is a more technical background to our work.
Immobilisation of metal ions from solution by the microorganism Desulphovibrio has been studied by two of us (JHPW & DCE ). In this work it was found that heavy metal ions with insoluble sulphides are removed from solution to residual levels less than 1 ppb. Further each bacterium can take on a considerable fraction of it's own weight and in many cases 3 to 4 times it's own wet weight of metal sulphides such as iron or uranyl. We have worked with many other metals such as U, Ru, Sr, Co, Pu, Am, Ce, Cs and Zr of interest to the nuclear industry, Pt, Pd, Rh, Ru, Ir, Au, Ag, Fe, Co, Ni and Cu of interest to the precious metal industry and a number pollutant metals such as Hg and Cd. The fact that the human gut is populated by Desulphovibrio, and similar microorganisms, led us to consider the consequences of the exposure of humans to low levels of radioactive solutions in the presence of this concentrating mechanism for heavy metals in the gut. We concluded that the uptake of these materials may be strongly affected by the gut bacterial flora. The Department of Health gave us a grant to enable us to carry out research in order to elucidate these questions.
Sulphate reducing bacteria (SRB) are present in the anaerobic regions of the gut, namely the lower bowel, of humans. The predominant genus is Desulphoribric spp but organisms belonging to the Desulphotomaculum spp, Desulphobacter spp, Desulphomonas spp and Desulphobulbus spp were also identified. In 40 persons (20 British and 20 Africans) examined by Gibson and his coworkers, there was a close inverse relationship between SRB carriage in the gut and the presence of methane on the breath, the 14/20 British and 3/20 Africans in whom significant numbers of SRB were present all failed to produce breath methane; the remainder, in whom SRBS were not present in significant numbers, were all methane producers.
Our research has now revealed the presence of Desulphovibrio in the faeces of a volunteer with no breath methane and we have demonstrated that these microorganisms will precipitate dietary iron which appears in the faeces and which can be collected by magnetic separation. We have also been able to modulate the numbers of SRBS by dietary means. We have also discovered that the SRBS form large clusters of highly adsorbent iron sulphide which contain almost all the SRBs. These microorganisms will also precipitate/absorb most of the important toxic heavy metals and these are incorporated into the clusters of iron sulphide.